﻿110 
  

  

  Mr. 
  C. 
  A. 
  Sadler 
  on 
  the 
  

  

  bulb 
  was 
  so 
  placed 
  relatively 
  to 
  this 
  tube 
  that 
  the 
  axis 
  o£ 
  

   the 
  tube 
  passed 
  through 
  the 
  centre 
  o£ 
  the 
  anticathode 
  A 
  

   normally. 
  

  

  Fi-. 
  1. 
  

  

  f/l/fTH 
  

  

  ^^^Co 
  

  

  The 
  rays 
  from 
  A 
  passing 
  through 
  this 
  tube 
  impinged 
  on 
  the 
  

   radiator 
  Rj 
  consisting 
  o£ 
  a 
  rectangular 
  plate 
  of 
  the 
  metal, 
  the 
  

   secondary 
  rays 
  from 
  which 
  were 
  to 
  be 
  studied. 
  A 
  portion 
  of 
  

   the 
  secondary 
  rays 
  so 
  produced 
  passed 
  down 
  the 
  rectangular 
  

   brass 
  tube 
  D 
  lined 
  as 
  before 
  with 
  "2 
  cm. 
  aluminium, 
  and 
  a 
  

   plate 
  of 
  any 
  substance 
  placed 
  in 
  this 
  secondary 
  beam 
  provided 
  

   a 
  source 
  of 
  tertiary 
  rays. 
  

  

  The 
  intensity 
  of 
  the 
  primary 
  beam 
  was 
  measured 
  by 
  

   allowing 
  a 
  narrow 
  pencil 
  of 
  rays 
  proceeding 
  from 
  A 
  through 
  

   a 
  small 
  aperture 
  in 
  the 
  lead 
  screen 
  SS 
  to 
  enter 
  an 
  electro- 
  

   scope 
  El 
  of 
  the 
  ordinary 
  Wilson 
  type 
  through 
  an 
  opening 
  

   covered 
  with 
  tissue-paper 
  and 
  aluminium-foil 
  in 
  the 
  wall 
  of 
  

   the 
  electroscope. 
  

  

  The 
  deflexions 
  of 
  the 
  gold 
  leaf 
  were 
  observed 
  by 
  means 
  of 
  

   a 
  microscope 
  fitted 
  with 
  a 
  scale 
  in 
  the 
  eyepiece. 
  

  

  The 
  intensity 
  of 
  the 
  secondary 
  beam 
  was 
  measured 
  by 
  -means 
  

  

  